Re: Abiogenesis and the primordial soup was Re: NTSE #11

Pim van Meurs (
Tue, 18 Mar 1997 22:05:41 -0400

I have been doing some research and would like to address some of your
remarks in your previous posting.

Your reference stated that no evidence had been found of nitrogen in
sedimentary rock dating back to the 'primordial' earth. Just recently
Homna published a
paper detailing the ammonium content of the Greenland Isua rock [1]

"All these data imply that clay minerals were the major sink of NH4+ or
nitrogen compounds on the Earth's surface at 3800 Ma."

Furthermore analysis of the rock in Greenland found evidence of amino
acids [2].
However let me point out to you that the authors do not believe these to
be from
3800 Myr ago but more recent. They notice that the rock had been exposed
temperatures 400- 600 C leading to a likely destruction of aminoacids in
original rock.

"Laboratory experiments show that amino acids and aromatic and saturated
aliphatic hydrocarbons, including pristane could not have survived the
methmorphic history of the Isua rock."

You mentioned the fossil evidence in the Greenland rock. Bridgewater et al
warn that these might not be fossils after all. Although other data
suggest the existance
of biotic material (C13 contents for instance). This is not too relevant
although if true it
would be evidence of life earlier than previously expected.

Marshall [4] shows that amino acids can be synthesized rapidly in
solutions from reactants that may have been present in primitive
This contradicts Miller et al's assertions that aminoacids would be
destroyed under
hydrothermal conditions.

Fox [5] addresses the implications of Marshall's paper and addresses his
findings of formation of 'protocells' modeled by experiments in self
organization of thermally induced proteins. He indicates that these cells
characteristics of metabolism, growth, reproduction and cellular response

Shock looked at theoretical and experimental results indicating that
temperatures favour dehydration reaction among organic compunds in aqueous
solutions. Reactions include amide formation from carboxylic acids and
and peptide formation from amino acids.

My preliminary research indicates that these old sediments might after all
show evidence of nitrogen inclusion, although the Greenland rock has been
exposed to high temperatures which would have destroyed aminoacids.
the hydrothermal vents suddenly pop up as viable alternatives to the
Miller/Urey synthesis or the extraterrestrial origin of amin oacids.



[1] High ammonium contents in the 3800 Ma Isua supercrustal rocks, central
Greenland, Honma, H., Geochimica et Cosmochimica Acta, vol 60(12),

[2] Aminoacids and hydrocarbons ~3,800 Myr old in the Isua rocks,
Greenland, Nagy, B et al, Nature, vol 289, 53-56, 1981

[3] Microfossil-like objects from the Archaean of Greenland: a cautionary
Bridgewater, D. et al, Nature, vol 289, 51-53, 1981

[4] Hydrothermal synthesis of amino acids, Marshall, W.L., Geochimica et
Cosmochimica Acta, vol 58(9) 2099-2106, 1994.

[5] Thermal synthesis of amino acids and the origin of life, Fox, S.W.,
Geochimica et Cosmochimica acta, vol. 59(6), 1213-1214, 1995.

[6] Hydrothermal dehydration of aqueous organic compounds, Shock E.L.,
Geochimica et Cosmochimica acta, vol 57, 3341-3349, 1993.